Right now my air quality app shows my neighborhood as having good air with an AQI of 14, but an area just a few miles away has an AQI of 129. How is this even possible? Surely even with wind there would be residual pollutants? Both places are outside of a big city, roughly 15-20 miles away from the city center.
ETA: the pollution is mainly due to PM2.5 and PM10. I live near Seoul.